Imo that shouldn't even be a feature on public forums; if you're on the forum you already agree to its contents, and it forum moderators find it fine why self-censor?
Afaik someone posting positively about AI one day doesn't necessarily define their character or who they are; they might talk about something completely different like source code for something on ports; would you benefit from not seeing potentially useful information because of past discussion? Maybe later they'll post something anti-AI, but it wouldn't be seen because of the previous AI-related ignore block.
Worst-case I imagine it affects conversation flow on threads if someone is willingly blocking posts from one user and selectively responding (when they could respond to the blocked poster and have others able to be included too; the block only serves
privately on a public forum); I prefer organic anything-goes